<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <link rel="stylesheet" href="./1.css">
  <link rel="stylesheet" href="./qq/qq.css">
</head>

<body>
  <h1>hello world</h1>
  <ul id='ul'></ul>
  <button id='btn'>点我</button>
</body>
<script src="./1.js"></script>

</html>